Answer:
5323
Step-by-step explanation:
453
Let 
be the random variable for the number of marks a given student receives on the exam.
10% of students obtain more than 75 marks, so
where 
follows a standard normal distribution. The critical value for an upper-tail probability of 10% is
where 
denotes the CDF of , and 
denotes the inverse CDF. We have
Similarly, because 20% of students obtain less than 40 marks, we have
so that
Then 
are such that
and we find
Answer:
1/3
Step-by-step explanation:
add all of the totals including the missing pair
we now have 24
7+1 is 8
24 minus 8 is 16
24 can be split into 2 groups of 8
and we have 2/3 left. which makes our solution 1/3
Answer:
B) 5.5
Step-by-step explanation:
